UltraSPARC has special sets of global registers which are switched to
for certain trap types. There is one set for MMU related traps, one
set of Interrupt Vector processing, and another set (called the
Alternate globals) for all other trap types.
For what seems like forever we've hard coded the values in some of
these trap registers. Some examples include:
1) Interrupt Vector global %g6 holds current processors interrupt
work struct where received interrupts are managed for IRQ handler
dispatch.
2) MMU global %g7 holds the base of the page tables of the currently
active address space.
3) Alternate global %g6 held the current_thread_info() value.
Such hardcoding has resulted in some serious issues in many areas.
There are some code sequences where having another register available
would help clean up the implementation. Taking traps such as
cross-calls from the OBP firmware requires some trick code sequences
wherein we have to save away and restore all of the special sets of
global registers when we enter/exit OBP.
We were also using the IMMU TSB register on SMP to hold the per-cpu
area base address, which doesn't work any longer now that we actually
use the TSB facility of the cpu.
The implementation is pretty straight forward. One tricky bit is
getting the current processor ID as that is different on different cpu
variants. We use a stub with a fancy calling convention which we
patch at boot time. The calling convention is that the stub is
branched to and the (PC - 4) to return to is in register %g1. The cpu
number is left in %g6. This stub can be invoked by using the
__GET_CPUID macro.
We use an array of per-cpu trap state to store the current thread and
physical address of the current address space's page tables. The
TRAP_LOAD_THREAD_REG loads %g6 with the current thread from this
table, it uses __GET_CPUID and also clobbers %g1.
TRAP_LOAD_IRQ_WORK is used by the interrupt vector processing to load
the current processor's IRQ software state into %g6. It also uses
__GET_CPUID and clobbers %g1.
Finally, TRAP_LOAD_PGD_PHYS loads the physical address base of the
current address space's page tables into %g7, it clobbers %g1 and uses
__GET_CPUID.
Many refinements are possible, as well as some tuning, with this stuff
in place.
Signed-off-by: David S. Miller <davem@davemloft.net>
Also, the Solaris syscall table is sized differrently,
and does not go beyond entry 255, so trim off the excess
entries.
Signed-off-by: David S. Miller <davem@davemloft.net>
This also includes by necessity _TIF_RESTORE_SIGMASK support,
which actually resulted in a lot of cleanups.
The sparc signal handling code is quite a mess and I should
clean it up some day.
Signed-off-by: David S. Miller <davem@davemloft.net>
Don't clobber register %l0 while checking TI_SYS_NOERROR value in
syscall return path. This bug was introduced by:
db7d9a4eb7
Problem narrowed down by Luis F. Ortiz and Richard Mortimer.
I tried using %l2 as suggested by Luis and that works for me.
Looking at the code I wonder if it makes sense to simplify the code
a little bit. The following works for me but I'm not sure how to
exercise the "NOERROR" codepath.
Signed-off-by: David S. Miller <davem@davemloft.net>
We need to use stricter memory barriers around the block
load and store instructions we use to save and restore the
FPU register file.
Signed-off-by: David S. Miller <davem@davemloft.net>
Instead of code patching to handle the page size fields in
the context registers, just use variables from which we get
the proper values.
Signed-off-by: David S. Miller <davem@davemloft.net>
At boot time, determine the D-cache, I-cache and E-cache size and
line-size. Use them in cache flushes when appropriate.
This change was motivated by discovering that the D-cache on
UltraSparc-IIIi and later are 64K not 32K, and the flushes done by the
Cheetah error handlers were assuming a 32K size.
There are still some pieces of code that are hard coding things and
will need to be fixed up at some point.
While we're here, fix the D-cache and I-cache parity error handlers
to run with interrupts disabled, and when the trap occurs at trap
level > 1 log the event via a counter displayed in /proc/cpuinfo.
Signed-off-by: David S. Miller <davem@davemloft.net>
Arrange the modules, OBP, and vmalloc areas such that a range
verification can be done quite minimally.
Signed-off-by: David S. Miller <davem@davemloft.net>
Current uncorrectable error handling was poor enough
that the processor could just loop taking the same
trap over and over again. Fix things up so that we
at least get a log message and perhaps even some register
state.
In the process, much consolidation became possible,
particularly with the correctable error handler.
Prefix assembler and C function names with "spitfire"
to indicate that these are for Ultra-I/II/IIi/IIe only.
More work is needed to make these routines robust and
featureful to the level of the Ultra-III error handlers.
Signed-off-by: David S. Miller <davem@davemloft.net>
Verify we really are taking a data access exception trap, at TL1, from
one of the window spill/fill handlers.
Else call a new function, data_access_exception_tl1, to log the error.
Signed-off-by: David S. Miller <davem@davemloft.net>
1) Read ASI_IMMU SFSR not ASI_DMMU.
2) IMMU has no SFAR, read TPC instead
3) Delete old and incorrect comment about the DTLB protection
trap having a dependency on the SFSR contents in order to
function correctly
Signed-off-by: David S. Miller <davem@davemloft.net>
These two bits were accesses non-atomically from assembler
code. So, in order to eliminate any potential races resulting
from that, move these pieces of state into two bytes elsewhere
in struct thread_info.
Signed-off-by: David S. Miller <davem@davemloft.net>
Also fix a bug in 32-bit syscall tracing. We forgot to update
this code when we moved over to the convention that all 32-bit
syscall arguments are zero extended by default.
Signed-off-by: David S. Miller <davem@davemloft.net>
This allows a PCI controller to shim into IRQ delivery
so that DMA queues can be drained, if necessary.
If some bus specific code needs to run before an IRQ
handler is invoked, the bus driver simply needs to setup
the function pointer in bucket->irq_info->pre_handler and
the two args bucket->irq_info->pre_handler_arg[12].
The Schizo PCI driver is converted over to use a pre-handler
for the DMA write-sync processing it needs when a device
is behind a PCI->PCI bus deeper than the top-level APB
bridges.
While we're here, clean up all of the action allocation
and handling. Now, we allocate the irqaction as part of
the bucket->irq_info area. There is an array of 4 irqaction
(for PCI irq sharing) and a bitmask saying which entries
are active.
The bucket->irq_info is allocated at build_irq() time, not
at request_irq() time. This simplifies request_irq() and
free_irq() tremendously.
The SMP dynamic IRQ retargetting code got removed in this
change too. It was disabled for a few months now, and we
can resurrect it in the future if we want.
Signed-off-by: David S. Miller <davem@davemloft.net>
The only real user was the assembler floppy interrupt
handler, which does not need to be in assembly.
This makes it so that there are less pieces of code which
know about the internal layout of ivector_table[] and
friends.
Signed-off-by: David S. Miller <davem@davemloft.net>
In particular, avoid membar instructions in the delay
slot of a jmpl instruction.
UltraSPARC-I, II, IIi, and IIe have a bug, documented in
the UltraSPARC-IIi User's Manual, Appendix K, Erratum 51
The long and short of it is that if the IMU unit misses
on a branch or jmpl, and there is a store buffer synchronizing
membar in the delay slot, the chip can stop fetching instructions.
If interrupts are enabled or some other trap is enabled, the
chip will unwedge itself, but performance will suffer.
We already had a workaround for this bug in a few spots, but
it's better to have the entire tree sanitized for this rule.
Signed-off-by: David S. Miller <davem@davemloft.net>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
